I should have stated that I have paid all the additional fees - I haven't attempted to skirt them. Now it's a question of how do I get them to indicate that they have been paid in "full."

They will report them as paid when they are paid, but it won't erase the fact that the payments were late or that the account was closed due to non-payment. As for getting it to show up on your credit report, just wait a month after the last payment was sent in, contact the credit agencies and see if it was updated. If it was, do nothing, if it wasn't then dispute the information.